Seamless Probabilistic Forecasts for Civil Protection: from week to minutes

Transcription

1 Seamless Probabilistic Forecasts for Civil Protection: from week to minutes Yong Wang, Clemens Wastl, Andre Simon, Mihaly Szűcs ZAMG and HMS

2 An EU project Bridging of Probabilistic Forecasts and Civil Protection Project: ; Website: Project aim Weather service and civil protection agency work together on: An innovative seamless probabilistic forecasting system in time (week to hour) and space (30km to 1km) tailored to civil protection

3 Seamless forecasts & actions ECMWF-EPS ~ 30 km resolution 15 days Civil Protection RESPONSE Potential severe weather event ALADIN-LAEF 11km resolution 3 days Civil Protection PREPARE More precise forecast AROME-EPS 2.5 km resolution 1,5 days Civil Protection GO-action Detailed forecast Ensemble INCA 1 km resolution 0-6 hours

4 Ensemble prediction systems ECMWF EPS 30km AROME EPS, AROME RUC and EN-INCA AROME EPS 2,5km EN-INCA 1 km AROME RUC 1,2km ALADIN-LAEF 11km

5 ALADIN-LAEF

6 Surface perturbation

7 Atmospheric perturbation

8 Stochastic surface physics

9 AROME-EPS AROME-EPS ensemble size Δx / vertical levels 2.5 km / 90 coupling runs per day IC perturbation model perturbation ECMWF EPS 2 / 4 runs (+30h forecast) EDA + EnJk +seda SPPT / psppt / ssppt: total tendencies (SPPT) micro-physics shallow convection turbulence

10 AROME-EPS: stochastic physics SPPT_global SPPT_adapt Influence of tapering function

11 Total tendencies Radiation scheme AROME-EPS Partial tendencies Radiation scheme δtt 1 δtt Shallow convection scheme δtt 2 δtt, δrr 2 δtt, Turbulence scheme δuu 2, VV 2 δtt δtt 3 δtt, δrr 3 δtt, δuu 3, VV 3 δtt Microphysics scheme δtt 1 δtt (1 + PP) Shallow convection scheme ( δtt 2 δtt, δrr 2 δtt, δuu 2, VV 2 ) (1 + PP) δtt Turbulence scheme ( δtt 3 δtt, δrr 3 δtt, δuu 3, VV 3 ) (1 + PP) δtt Microphysics scheme 4 dddd dddd = δttii δtt ii=1 δtt 4 δtt, δrr 4 δtt (1 + PP) dddd dddd = ( δtt 4 δtt, δrr 4 δtt 4 dddd dddd = δttii δtt ii=1 ) (1 + PP) dddd dddd =

12 Ensemble INCA: Details EN-INCA Precipitation Analysis Nowcasting blending NWP Measurement error * Representation error * Radar error * Interpolation error * Extrapolation error Convective effects* NWP errors / Folie 12 uncertainties and/or Multi-Modelapproach * Measurement error* Representation error * Interpolation error * Ensemble background fields Error in NWP-trend -> LAEF Stochastical blending with LAEF NWP errors / uncertainties Perturbed META (Objectively Optimized Forecasting System) Analyse Nowcasting blending NWP Temperatur, wind

13 Estimation of radar error Error stdev

14 Ensmeble INCA From Error motion vectors to a nowcasting ensemble Error motion vector based on the error of previous motion vectors (e.g. last minutes) random variation of error motion vector (within Gaussian distr.) yields spread beginning at the very first forecast time step

15 Examples of ensemble precipitation analysis

16 Statistical calibration

17 Webpage:

18 Webportal

19 Threat by impact! Threat level: Impact definded by Civil Protection! - Combination of probability and impact - 3 warning levels: yellow, orange, red - Also the forecast time plays a role: The farther into the future the more severe a potential event has to be to reach threat level - General decay of forecast quality with increasing lead time is acknowledged in that way

20 Case studies Storm Niklas March 30 April days before the event: ECMWF-EPS First signals of a heavy storm event are already visible - first awareness actions in the forecasting centres. ECMWF forecast for Tuesday March 31, 18 UTC (Init UTC). Probability of gusts > 60km/h (up) and > 80km/h (right). ECMWF Meteogram for the capital city of St. Pölten (Init UTC). Some members exceed the 100km/h threshold for this location.

21 Case studies Storm Niklas March 30 April days before the event: LAEF LAEF with a horizontal resolution of 11km includes more orographic details and confirms the forecast of ECMWF-EPS. CP receives first official warnings warning level was upgraded to orange. Local authorities are informed, first preparation actions are launched. Official warning of ZAMG issued on March UTC. Warning level was upgraded to orange (annuality < 3 times a year). LAEF forecast for Tuesday March 31, 18 UTC (Init UTC). Probability of gusts > 60km/h (upper), > 80km/h (middle) and > 100km/h (lower).

22 Case studies Storm Niklas March 30 April day before the event: AROME-EPS Convection permitting EPS system AROME with 2.5km resolution and 48 hours forecasting range. Warning level orange was extended in time, basic warning was increased to 100km/h for the western parts of Lower Austria - final preparedness and prevention actions in CP are launched. AROME-EPS forecast for Tuesday March 31, 17 UTC (Init UTC). Probability of gusts > 60km/h (left), > 80km/h (middle) and Ensemble max. wind speed (right).

23 Case studies Storm Niklas March 30 April Nowcasting: Ensemble-INCA 1km resolution, 12h forecasting range, 15min update interval.warning level orange was extended in time, basic warning was increased to 100km/h for the western parts of Lower Austria - final preparedness and prevention actions in CP are launched. Ensemble-INCA forecast for Tuesday March 31, 14 UTC (Init UTC). Probability of gusts > 80km/h (left) and Ensemble max. wind speed (right).

24 Case studies Storm Niklas March 30 April Feedback from Civil Protection - Very good wind forecasts of the seamless system - First awareness already several days in advance (much earlier than deterministic) - Additional information about uncertainty helped to focus the CP forces - Very high correspondence of warnings and number of operations Map of Upper Austria (left) and Lower Austria (middle) with marked operations due to strong wind. A comparison with the seamless forecast of the event (probability of exceeding 60km/h) shows the very high correspondence between operations and forecast.

25 A severe windstorm over Hungary 6 days before the event (Tuesday, 28 April 2015) Maximum gust (can exceed 90 km/h) ECMWF-EPS: Somogy county 1. Windstorm from NW 2. In the morning (peak at 09 UTC), 3. North of the county (Lake Balaton) 4. probability: 20-30% over 70km/h

26 A severe windstorm over Hungary 4 days before the event (Tuesday, 28 April 2015) Maximum gust (70-80 km/h) ECMWF-EPS: Change! In the evening (peak at 18 UTC)! probability: 50-60% over 70km/h! Intensity weaker!

27 A severe windstorm over Hungary 3 days before the event (Tuesday, 28 April 2015) Maximum gust (70-80 km/h) ECMWF-EPS: Probability: 40% over 70km/h! No probability for 90km/h. Intensity even weaker! Weak thunderstorm! EPS Maximum for thunderstorm index Average intensity thunderstorms Showers, weak thunderstorms

28 A severe windstorm over Hungary 1 days before the event (Tuesday, 28 April 2015) Maximum gust (70 km/h) ALADIN-EPS: Change! not realistic Somogy county peak at 21 UTC! probability: 50% over 70km/h, but no > 90 km/h Intensity weaker! Shower, thunderstorm possible

29 A severe windstorm over Hungary The day of the event, in the morning (Tuesday, 28 April 2015) Maximum gust (70 km/h) ALADIN-EPS: No important change! The maximum gust even a bit weaker. Thunderstorm possible, weak to normal! EPS Maximum for thunderstorm index

30 The event 1400 UTC (Tuesday, 28 April 2015) INCA-EPS 3h nowcasts: Frontal precipitation approaching the area of Balaton, convective pre-frontal cells coming from south INCA EPS Wind analysis and nowcast: The wind will reach gale intensity at Balaton within 3h Analysis 3h forecast

31 Caution! Day of the event 1700 UTC (Tuesday, 28 April 2015) Wind analysis and nowcast: The wind already turned at Balaton and intensified (70-90 km/h gusts) as planned. But the INCA nowcasts indicate that the wind can reach 100 km/h as well. This was not forecast by ECMWF and ALADIN-EPS!!! 100 km/h Analysis +3h Forecast

32 The event 1700 UTC (Tuesday, 28 April 2015) Observations confirmed! Windstorm at Balaton is already strong, the front reached the inner part of the County as well. The stable cold air inhibits convection. Heavy cells are only at the south. Siófok at Balaton: gale Kaposvár: after rain, windy roll-clouds waves

33 The event 2000 UTC (Tuesday, 28 April 2015) INCA-EPS 3h precipitation nowcasts: Heavy precipitation is aready out of the Somogy County. But the gale at Balaton further intensified!!! But INCA can sometimes overestimate the gust speed. We might verify it... EPS INCA maximum precipitation INCA wind analysis gusts > 110 km/h

34 The event 2000 UTC (Tuesday, 28 April 2015) Wind gusts and average windspeed at Balatonőszöd (central basin and southern shore of the Lake) 139 km/h 2000 UTC

35 IMPACT, after the event (Wednesday, 29 April 2015) Impact of : Damaged power lines on the railway at Balaton, buildings, ships in the harbour of Siófok. About 17 rescue actions required.

36 Summary and Follow up In the frame of PROFORCE, 4 weather and civil protection partners from Austria and Hungary have worked together on: An innovative seamless probabilistic forecasting system in time and space tailored to civil protection, for: improvements in the accuracy and timeliness of severe weather warnings improved preparedness and decision making procedures in civil protection agencies cooperation between weather and civil protection authorities transnational cooperation on warning Adaptation of the developed system for further use in other European countries and in other application area

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